Reviewer:

I was going to give this four stars, but then my husband commented how much he loved it, so it went up to five. I do have a couple of notes, though ... the first being that corn oil or canola oil may make a slight difference in flavor, but honestly, one really isn't better than another.
Yes, you can bump this up to do what you need it to - add garlic, additional herbs, etc., but this is IMPORTANT: do NOT leave it on the counter, as one poster has mentioned. While the oils and vinegar are fine, the herbs will spoil if this is not kept in the fridge. You still shouldn't keep it more than two weeks.
Yes, if you keep it in the fridge, it will thicken and separate. An easy way around that is to keep this in a mason jar. You don't have to whisk it every time - just shake away. It'll thin out and mix well, and be ready for the next use.

Reviewer:

I realized after prepping all my ingredients that we were out of Italian dressing. This recipe saved my salad! We did tweak it a bit. I used only olive oil, we don't use any other vegetable oil. We also used fresh herbs from the garden: sage, thyme, basil, and fresh pressed garlic. I didn't have dried oregano, so subbed a bit of Italian seasoning. The only reason I gave it four stars, was because it was oily (compared to store bought) on the lips and tongue when eating it. This may be because it was a home made dressing, I don't know. I have never made my own before. This dressing went on my quinoa and fresh veggie salad. My friend is gluten and dairy free, and she loved it. Thank you!